1. Field of the Invention
This invention generally relates to the field of electroacoustic transducers such as hydrophones and more specifically to an apparatus and technique for coupling magnetically a plurality of electroacoustic transducers or hydrophones to a single conductor trunk cable using seawater as the electrical return path.
2. Statement of the Prior Art
One of the common requirements in most of the oceanographic communication studies is to collect at the shore end of a trunk cable acoustic data which is transmitted from a cooperative underwater target in order to determine its position in three dimensions as a function of time. For such applications, metallic connections using either underwater connectors or premolded splices have been used to connect a plurality of hydrophones to the trunk cable. This puts pre-deployment constraints on the location of hydrophones and complicates the deployment process as any discontinuity (e.g., a connector) must be passed through pulleys, drums and other apparatus as required to hold and properly deploy miles of trunk cable. Trunk cables used in the past for such applications have typically employed two conductor-cables usually in a coaxial configuration which puts an additional constraint in deploying long lengths of such cable. It is thus desirable to have an apparatus which can improve deployment of a trunk cable which avoids the use of connector and uses a single conductor cable.